Thousands of Guatemalans have marched through the capital to demand the resignation of President Alvaro Colom over the killing of a lawyer.
Before his death lawyer Rodrigo Rosenberg recorded a video saying that if he was found dead the President and his aides would be responsible.
The tape was released the day after the 47-year-old was shot dead on 10 May.
Mr Colom has denied involvement in the killing, and his supporters staged a rival demonstration in Guatemala City.
President Colom, the Central American country's first left of centre leader for half a century, has called on the US Federal Bureau of Investigation and a United Nations panel to investigate.
Mr Rosenberg alleges that he would have been killed because of his links to a client, a prominent businessman, who was killed in March with his daughter.
In the video Mr Rosenberg calmly says: "If you are watching this message, it is because I was assassinated by President Alvaro Colom with help from Gustavo Alejos."
He was shot dead a few days later while riding a bicycle.
The government has described the allegations against Mr Colom as a conspiracy to destabilise Guatemala.
Demonstrations by both sides over the week have been escalating the crisis which analyst say could threaten Guatemala's fragile democracy.
The country remains deeply divided, more than a decade after the end of its civil war, between a ruling elite and a largely indigenous population of poor farmers and labourers.